新概念英語4學習筆記：第18課 Porpoises
本文選自吳應時的《應時新概念英語4》，是學習新概念英語第四冊的輔助學習筆記，提供知識點精講及解析，想知道具體都有哪些內容，那就一起來看看吧。
第一段語法符號詳解：
1. There has long been a superstition that porpoises will save men or protect them…
複合句，主句爲 there be 句型，然後有一個 that 引導的同位語從句. 該從句爲並列句，主謂賓結構.
2. biologists have pointed out that it is a mistake to credit…
複合句，主句爲主謂+that 引導的賓語從句.該賓語從句亦是複合句，包括 however 引導的讓步狀語從句，以及主系表結構的主句，主句中動詞不定式作真正的主語.
3. when…they have done it…
複合句，when 引導時間狀語從句在前，爲主謂賓結構. 主句爲主謂賓結構，主句中 as 引導的方式狀語有省略，as they did in riding the bow waves…
4. some porpoises were photographed…
簡單句，被動語態的主謂結構，加上主語補足語作補充說明. working like beavers 爲伴隨狀語. Someone photographed some porpoises
5. If…they have protected humans…, it may have been because…and because…
複合句，if 引導的條件狀語從句爲主謂賓結構，其中包括 as 引導的定語從句. (2.2.1)
主句爲主系表結構，爲並列句，and 連接兩個表語從句. 表語從句均爲主謂賓結構.
6. Porpoises and sharks are enemies.
簡單句，主系表結構.
7. It is possible that… a battle ensued…
複合句，it 作形式主語. 真正的主語由 that 引導的主語從句擔任，該主語從句爲主謂結構.
第二段語法符號詳解：
1. Whether…the porpoise is intrigued with anything that is…
複合句，主句爲主謂賓結構，賓語 anything 由 that 引導的定語從句修飾. 開頭是 whether 引導的讓步狀語從句. 該從句爲主系表結構.
2. They are after the turtles who…
複合句，主句爲主謂賓結構，be after 爲動詞詞組. who 引導的定語從句爲主謂賓結構，修飾 turtles.
3. One young calf enjoyed raising… and shoving…
並列句，主句爲主謂賓結構，兩個動名詞 raising 和 shoving 作 enjoy 的賓語.
4. a young porpoise may be seen…
簡單句，主句爲被動語態的主謂結構，同樣的，後面的補語在非被動語態中作賓語補足語，而現在則作該被動語態中的主語補足語.
by 引導的方式狀語本身比較長，是並列結構，可以看成是 by sticking and by pushing.
for dear life 爲 for one's life 的變體，拼命之意.
5. This is not easy and (this) may require two porpoises…
並列句，首句爲主系表結構，後句省略了主語，爲主謂賓+賓補結構.
6. the first porpoise swoops down…and butts…
並列複合句，主句爲主謂賓結構，後句省略了主語.
as 引導的時間狀語從句爲主謂結構.
7. This knocks down the turtle…
簡單句，主謂賓結構，謂語由動詞詞組擔任.
8. He recovers his equilibrium than the next porpoise comes along and hits…
複合句，主句主謂賓結構.
從句爲並列句，主謂賓結構，第二句省略了主語，(the next porpoise) hits him another crack 雙賓語，him 爲間接賓語，another crack 爲直接賓語.
這裏是 no sooner…than 結構的時間狀語從句，語法上，主句用過去完成時，從句用一般過去時. 本句可寫作：No sooner had he recovered his equilibrium than the next porpoise came along and hit him another crack.
9. the turtle has been butted…
簡單句，主謂結構.
10. He is satisfied to try… but a porpoise knocks him…
並列複合句，but 分成前後兩句.
第一句爲主謂賓結構.
第二句爲 as soon as 引導的時間狀語從句，以及主句爲主謂賓+賓補結構.
11. The turtle gives up and the game is over…
並列句，第一句主謂結構，第二句主系表結構.
